Mash the potato while the boiled potatoes are still hot, then allow to cool before adding in the spring onion and seasoning. Lightly whisk the flour and baking powder with the milk (100ml at first) and zest and add to the mash, whisking in.
Check the seasoning and consistency (add a little extra milk if the mix is too stiff, but it should still be thick). Heat the olive oil in a large non-stick frying pan. When hot, pour in the batter, using a spatula to spread the mix out as its quite thick. When the pancake has puffed up and browned beneath (about 2 minutes), carefully flip over to cook on the other side.
To serve, place a pancake on each plate, top with the smashed avocado (seasoned with salt & pepper and lemon juice), a handful of watercress and the smoked salmon.
If you are adding a poached egg, place this on top of the salmon. Squeeze extra lemon and drizzle a little olive oil over the top.
TIP Leftover mashed potatoes can be used in this recipe.
200g fluffy potatoes (such as Maris Piper), diced, boiled, drained and mashed (or used leftover mashed potato)
2 spring onions, finely chopped
1tsp baking powder
75g plain flour
100-150ml whole milk
1 lemon, zest only (reserve lemon for juice)
½tbsp olive oil to cook
1 avocado, loosely mashed
150g smoked salmon
handful watercress (optional), to serve (or rocket, if preferred)
1 egg, poached (optional)